by Malini
QUESTION: I am a thin 28-year-old woman with hypothyroidism. My glucose was reported as 107 mg/dL, but I had tea during the night and again that morning, so I was not truly fasting. I have no parental history of diabetes and am now afraid to repeat the test. Does 107 mean prediabetes?
No—107 mg/dL cannot be classified as fasting prediabetes because you had tea before the blood test. It is a nonfasting result, and 107 mg/dL is not in the diabetes range for a random glucose test. Repeat a laboratory fasting glucose after at least eight hours with only plain water, or ask for an HbA1c, which does not require fasting. Hypothyroidism should be monitored separately with thyroid tests, but this one result is not a reason to assume diabetes or drastically restrict food.
Answer by Dr. Albana Greca, MD, MMedSc
Hi Malini,
Your test was not a valid fasting test because you drank tea that morning. Formal fasting instructions allow only water; sugar, honey, or milk add calories and can affect the result.
A random glucose of 107 mg/dL is reassuring. Diabetes is diagnosed from random glucose only when it is at least 200 mg/dL with classic symptoms such as excessive thirst, frequent urination, or unexplained weight loss. See how blood tests for diabetes are interpreted.
The fasting thresholds—below 100 mg/dL as normal, 100–125 mg/dL as prediabetes, and at least 126 mg/dL as diabetes—apply only after at least eight hours without calories. See the normal fasting blood sugar ranges.
An HbA1c test estimates average glucose over the previous two to three months and does not require fasting. If it disagrees substantially with fasting glucose, the clinician should investigate why.
Without clear symptoms or a hyperglycemic crisis, an abnormal diabetes result usually requires confirmation with a second abnormal result. Our blood sugar level chart provides the main ranges in mg/dL and mmol/L.
Untreated hypothyroidism may be associated with insulin resistance or altered glucose handling. However, a glucose of 107 after tea does not show that your thyroid medicine is inadequate.
Hypothyroidism can sometimes affect HbA1c interpretation. Assess thyroid control with TSH and, when indicated, free T4. Levothyroxine changes should be based on thyroid results and clinical review—not this glucose result.
Thin people can still develop prediabetes or diabetes, and no family history does not eliminate risk. Age, pregnancy history, medicines, endocrine conditions, and genetics also matter. Read about insulin resistance.
No drastic restriction is justified. Because you are very thin, unnecessary restriction could cause weight loss or nutrient deficiencies. Choose balanced meals with vegetables, protein, healthy fats, fruit, legumes, and high-fiber carbohydrates. See foods and blood sugar.
One teaspoon of sugar does not diagnose diabetes. The priority is accurate testing, not trying to force the result lower beforehand.
If you are pregnant or planning pregnancy, tell the clinician because testing targets differ. Review the symptoms of type 2 diabetes, remembering that testing makes the diagnosis.
Arrange prompt medical testing if you develop excessive thirst, frequent urination, blurred vision, recurrent infections, or unexplained weight loss. Seek urgent care for vomiting, difficult breathing, confusion, severe dehydration, ketones, or very high glucose. Do not change levothyroxine or begin diabetes medicine based on this single nonfasting result.
A value of 107 mg/dL after tea is neither a valid fasting result nor evidence of diabetes. Repeat the test under correct conditions and review your thyroid control normally. There is no medical benefit in being frightened of testing—the result provides information that allows either reassurance or early, manageable action.
Educational safety note: This answer is for general diabetes and thyroid education only. It does not replace personal medical advice, diagnosis, or treatment. Do not change thyroid medicine, begin diabetes medicine, or adopt a restrictive diet without speaking with your healthcare provider.
Last reviewed: July 2026.
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